An incandescent light bulb, incandescent lamp, or incandescent light globe is an electric light which produces light with a filament wire, suspended in a near vacuum and heated to a high temperature by an electric current passing through it, until it glows producing light. The hot filament is protected from oxidation with a glass bulb that is evacuated and partially filled with inert gas usually at a pressure lower than the atmosphere. The light bulb filament is supplied with electrical current by feed-through terminals or wires embedded in a glass stem that supports the filament. Most bulbs are made for use in a socket which provides mechanical support and electrical power.
Incandescent bulbs are manufactured in a wide range of sizes, light output, and voltage ratings, typically from 1.5 volts to about 300 volts. They require no external regulating equipment, have low manufacturing cost, and may be powered by either alternating current or direct current. As a result, the incandescent lamp is widely used in household and commercial lighting, for portable lighting such as table lamps, car headlamps, and flashlights, and for decorative and advertising lighting.
Because of their inefficiency, incandescent light bulbs are gradually being replaced in many applications by other types of electric lights, such as fluorescent lamps, compact fluorescent lamps (CFL), cold cathode fluorescent lamps (CCFL), high-intensity discharge lamps, and light-emitting diodes (LEDs). However, one area that has not received attention is improving power efficiency for decorative lighting because the focus of development has often been in improving lighting efficiency, and replacing bulbs used for simple lighting rather than provide efficient decorative lighting. Therefore, it would be advantageous to provide a power efficient decorative light device that utilized existing incandescent bulb sockets.